Textile apparatus



Jan. 10, 1967 E p sc ETAL 3,296,789

TEXTILE APPARATUS Filed April 7, 1966 2 Sheets-Sheet l 1967 E. P. R. SCRAGG ETAL 3,296,789

TEXTILE APPARATUS Filed April 7, 1966 2 Sheets-Sheet 2 3,296,789 TEXTELE APPARATUS Ernest Philip Rushton @cragg, Macclestield, Walter Parlier, Wilnislow, and Harold William Lee, Poynton, England, assignors to Ernest Scragg 8: Sons Limited, Macclesiield, England Filed Apr. 7, 1966, Ser. No. 541,937 Claims priority, application Great Britain, Apr. 8, 1965, 14,933/ 65 24 Claims. (Cl. 57-77.45)

The present invention relates to a yarn twisting arrangement, and more particularly to yarn twisting apparatus for driving a false twist tube.

It is the main object of the invention to prevent a reduction of the rotary speed of a twist tube by friction.

Another object of the invention is to provide a drive apparatus for a twist tube in which the twist tube is not mechanically supported while being driven.

Another object of the invention is to urge a twist tube into driving engagement with drive means by a fluid pressure differential.

Another object of the invention is to move a twist tube into driving engagement with a rotary drive surface by means of an air current.

Another object of the invention is to balance a twist tube in axial direction by air currents acting in opposite axial directions along the twisting tubev With these objects in view, the present invention relates to apparatus for urging a false twist tube into engagement with driving and/ or supporting means by differential fluid pressure acting transversely of the twisting tube.

One embodiment of the invention comprises drive means having a drive surface; yarn twisting means, such as a false twist tube adapted to be rotated by being urged in a predetermined direction against the drive surface of the drive means; and means for creating a current of a fluid medium in the predetermined direction encompassing at least part of the twisting means for urging the same into driving engagement with the driving surface of the drive means.

In a preferred embodiment of the invention, the twisting arrangement comprises a yarn twist tube located adjacent drive means, such as drive roller means; holding means forming an open chamber with the twist tube; and gas moving means connected with the holding means and communicating with the chamber for creating a pressure differential in the region of the twist tube to urge the same toward and into driving connection with said drive means.

Since the drive rollers which rotate the twist tube also support the same during the twisting operation, the drive means may also be considered to be supporting means.

The chamber formed by the holding means is adapted for the entry and discharge of gas, such as air, since it is only partially closed by the twist tube. In one embodiment of the invention, the gas moving means is a suction pump connected by a conduit with the holding means and the chamber. In this construction, the chamber must be located on the same side of the twisting tube, as the drive means, since the pressure differential created by the suction pump between the chamber and the surrounding atmosphere urges the twist tube into the chamber.

In another embodiment of the invention, the gas moving means is a blower connected by a conduit with the holding means and communicating with the chamber so that a stream of air is blown out of the chamber and against the twist tube, moving the same away from the chamber. In this embodiment, the holding means and the chamber are located on the side of the twist tube remote from the drive roller means in order to urge nited States Patent M 3,296,78 Patented Jan. 10, 1967 the twist tube by an air current against the driving surface or surfaces of the drive roller means.

Since the twist tube is cylindrical, the inner surface of the chamber has a matching semicircular or semicylindrical contour, whose axis is parallel to the axis of rotation of the drive roller means. It is advantageous to provide the axially extending edges of the semi cylindrical chamber with lips projecting inward in substantially radial direction toward the cylindrical outer surface of the twist tube so that the chamber is partially closed to restrict the inward or outward flow of gas. Otherwise, the chamber may be constmcted to form a hydrodynamic gas bearing suitable for the high speed of rotation of the twist tube.

In accordance with the prior art, a false twist tube has collars engaged by drive means or supporting means for preventing axial displacement of the tube. In accordance with another embodiment of the invention, differential air pressure acting in axial direction on the twist tube is applied for maintaining the twist tube in a desired axial position in which its outer cylindrical surface is located opposite the drive surface or surfaces of the drive means. It is advantageous to provide the ends of the twist tube with conical collars forming semicircular gaps with the ends of the holding means which form the chamber, so that air passes through the gaps to maintain the collars of the twist tube spaced from the ends of the holding means.

The conduit which connects the chamber of the holding means with the air moving means, such as a suction pump or a blower, advantageously includes a restrictor valve limiting the flow of air in the event that the twist tube is removed.

In another embodiment of the invention, the twist tube has an enlarged portion of greater diameter forming a chamber with the semicylindrical holding means. In this embodiment, the gas orair blown into the chamber forms a hydrodynamic gas bearing sustaining a force exerted by the drive roller means on the twisting tube. This embodiment is particularly suited for the drive of the twist tube by one or more rollers having a common axis. In this case, the force urging the twist tube into engagement with the drive roller means, is advantageously directed along a line inclined to the plane connecting the axes of the twist tube with the axis of the roller means, so that lateral movements of the twist tube in the direction of movement of the engaged peripheral portion of the roller means is opposed by the air pressure.

In other embodiments of the invention, the drive means include one or more pairs of driving rollers, the rollers of each pair simultaneously engaging the twist tube for rotating the same.

Another aspect of the invention is the cooling of the twist tube by passing a current of a coolant gas over at least part of the tube. The stream of air blowing into the chamber for urging the twisting tube into driving engagement with the drive roller means, cools the twist tube if supplied at a sufficiently low temperature. From the above description of preferred embodiments of the apparatus of the invention, it will be appreciated that the invention also relates to a method of operating a twisting arrangement which comprises the step of moving a twist tube into engagement with driving and/or supporting means by creating a fluid pressure differential exerting a transverse force on the twisting tube. In the preferred method of the invention, the pressure differential creates a current of a coolant gas over at least part of the tube.

A plurality of twisting arrangements according to the invention is advantageously provided in a false twist crimping machine.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

FIG. 1 is a fragmentary, partly schematic elevation illustrating a first embodiment of the invention;

FIG. 2 is a fragmentary plan view of the embodiment of FIG. 1;

FIG. 3 is a fragmentary, partly schematic, elevation illustrating a second embodiment of the invention;

FIG. 4 is a fragmentary plan view of the embodiment of FIG. 3;

FIG. 5 is a fragmentary elevation illustrating a constructive detail of a third embodiment which otherwise corresponds to the embodiment of FIGS. 3 and 4;

FIG. 6 is a fragmentary plan view illustrating a fourth embodiment; and

FIG. 7 is an elevation, partially in section along line VIIVII in FIG. 6.

Referring now to the drawing, each of the four embodiments of the invention is a yarn twisting arrangement 11. In each embodiment, a false twist tube 12 is urged into, and held in engagement with the driving and/or supporting means shown to be two pairs of rollers 13 in the embodiments of FIGS. 1 to 5, and two coaxial rollers 13a in the embodiment of FIGS. 6 and 7.

In the embodiment of FIGS. 1 to 5, two drive shafts 14 respectively carry two rollers 13 spaced in axial direction and forming two axially spaced pairs of cooperating rollers, the rollers of each pair cooperating with axially spaced portions of a cylindrical twist tube 12 which has at the ends wider collars 12a which limit axial movement of twist tube 12 by engagement with the highest or lowest roller 13.

In the embodiment of FIGS. 1 and 2, a suction pump 17 is connected by conduit means 26 to a plurality of twisting arrangements 11, only one being shown in the drawing. The respective conduit 26 is connectedwith a pipe 16 secured to a holding means 21a which has a substantially semicircular cylindrical inner surface 21 extending about a part of twisting tube 12. The axially extending edges 23 of holding means 21a have radially inward projecting lips 22 whose ends are located in the close proximity of the outer surface of twisting tube 12, so that the walls of holding means 21a form together with one side of the outer surface of the twisting tube, a chamber 15 from which air is exhausted by suction pump 17. Holding means 21a has end walls at the ends of the cylindrical wall which have circular cutouts closely spaced from the outer surface of twist tube 12 when twist tube 12 is in a position engaging the peripheral circular surfaces of rollers 13. Small gaps are formed between the twisting tube 12, lips 22, and the edges of the cutouts in the end walls, and air enters through these gaps when chamber 15 is exhausted. Due to the throttling effects, the pressure in chamber 15 is far lower than the atmospheric pressure so that a pressure differential is created between the side of the twist tube closing chamber 15, and the diametrically opposite side of the twist tube on which atmospheric pressure acts. Consequently, the twist tube is urged into engagement with the peripheral surfaces of drive rollers 13, and rotated by the same.

In order to obtain a force acting to press twisting tube 12 against roller 13, holding means 21a and chamber 15 must be located on the same side of the twisting tube as the drive rollers 13.

It will be seen that no portion of cylindrical outer surface of the twisting tube 12 is in frictional engagement with any part of the holding means 21a, and that the air flowing through the gaps between holding means 21a and the twisting tube form a hydrodynamic bearing for the same.

In the event that the twisting tube of one twisting apparatus 11 is removed, the throttling effect of the gaps would be eliminated, and a great amount of air would be sucked through conduit 27 by suction means 17 so that the negative pressure of other twisting devices with which suction pump 17 is connected by conduit 26 would be insuflicient. Consequently, a restrictor valve 27 is provided in each conducit 26, which limits the amount of air sucked by suction pump 17 through any of the conduits 26.

In the embodiment of FIGS. 3 and 4, the pairs of rollers 13 and the twist tube 12 are disposed as explained with reference to FIGS. 1 and 2. However, the holding means 21a is located on the side of the twisting tube remote from shaft 14 and drive rollers 13, as best seen in FIG. 4. The construction of the holding means 21 is the same as explained with reference to FIGS. 1 and 2, but in the embodiment of FIGS. 3 and 4, a blower 19 is connected by conduits 26 and restrictor valve 27 to the several twisting devices, and more particularly to an inlet tube 18 opening into the chamber 15 of holding means 21a. The air current flowing into chamber 15 escapes through gaps between projecting lips 22, and the cutouts in the end walls of holding means 15, and this air current acts on the side of the twisting tube facing chamber 15, so that the twisting tube is urged to the right as viewed in FIGS. 3 and 4 into engagement with the peripheral faces of drive roller 13, and is rotated. The air in chamber 15 has a higher pressure than the air surrounding the diametrically opposite part of twisting tube 12, so that a pressure differential acts on twisting tube 12 to hold the same against the drive surfaces of the rollers. The embodiment illustrated in FIG. 5 corresponds in every respect to the embodiment of FIGS. 3 and 4, but the axial length of the semicircular wall of holding means 21b is increased so that the semicircular edges at the ends of holding means 2112 form narrow gaps with frustoconical surfaces 25 of collars 12a. Axially extending lips, not shown, are provided at the axially extending edges of the semicircular wall, and form longitudinally extending gaps with twisting tube 11, as described with reference to FIG. 4.

When air is blown into chamber 15, the effects explained with reference to FIGS. 3 and 4 will be obtained, and the higher pressure in chamber 15 will urge twist tube 12 into driving engagement with the peripheral surfaces of rollers The portions of conical surfaces 25 bounding chamber 15 at the axial end thereof, will be subjected to the higher pressure in chamber 15 and will be passed by air currents passing between edges 24 and conical surface 25 to the outside. Consequently, opposing axially directed forces will be exerted on collars 12a and on twisting tube 12 to maintain the twisting tube in a position of equilibrium in which the collars 12a are spaced from the highest and lowest drive rollers 13. For example, if twisting tube 12 drops out of the balanced position, the upper gap will be reduced, the pressure in the upper chamber portion of chamber 15 will increase, and act on surface 25 to raise the twisting tube, while the pressure in the lower portion of chamber 15 drops due to a greater amount of air being discharged through the widened gap.

In the embodiments of FIGS. 1 to 5, the holding means 21a or 21b is fixed during operation of the device.

However, since the position of holding means 21a and 21b in the embodiments of FIGS. 3 and 5 would prevent a removal of the twisting tube in radial direction away from roller 13, holding means 21a or 21b is mounted on a pivoted support permitting swinging of holding means to a position permitting removal of twisting tube 12. It is also possible to resiliently mount the holding means, so that it can be retracted from its illustrated operative position to an inoperative position in which twisting tube 12 can be moved inradial direction away from rollers 13 for inspection or servicing.

The embodiment illustrated in FIGS. 6 and 7 has drive means with only two axially aligned drive rollers 13a driven by a common shaft 14a. Twist tube 12' has a portion 12b of increased diameter located between the two rollers 13a. A holding means 21c of substantially semi circular configuration has an inner cylindrical surface 25d Whose diameter is slightly greater than the diameter of portion 12b so that a narrow semicircular chamber 15a is formed between holding means 21c and portion 12b of the twisting tube. Since the chamber is narrow, no end walls and inwardly projecting lips are necessary.

Air pressed by a blower, not shown, through pipe 18a into a narrow chamber 15;: increases the pressure in chamber 150 above the atmospheric pressure acting on the dia metrically opposite side of tube portion 1215 so that the pressure differential urges twist tube 12 into frictional driving engagement with the peripheral drive surfaces of rollers 13a. The air currents flowing from the inlet of pipe 18a in opposite directions along surface 21d, have the same effect.

Rollers 13a rotate in counterclockwise direction so that a force acting in tangential direction in relation to the peripheral surfaces of rollers 13a, acts on twisting tube 12b. Therefore, the plane of symmetry of holding means 21c and pipe 18 is not disposed in a plane passing through the axes of twist tube 121) and rollers 13a, but the plane of symmetry of holding means 21c defines an obtuse angle with the plane passing through the axes of twisting tube 121) and rollers 13a, so that a greater portion of surface 21d opposes the tangential force produced on the twisting tube 12b by drive roller 13a.

The air in the respective portion of chamber or gap 15a acts as an air cushion and hydrodynamic air bearing so that portion 121) does not friotionally engage the inner surface 21d.

In all embodiments of the invention, the air flowing along the twisting tube cools the same, which is of great importance since heating of the twisting tube due to the frictional engagement with the drive rollers is unavoidable.

When a row or series of twisting devices as described with reference to FIGS. 3 to 7 is mounted on the frame of a twisting machine, the respective chamber forming holding means are individually movable to inoperative positions to permit removal and insertion of a twist tube into the respective apparatus. As noted above, the holding means may be mounted on a pivoted support, or on resilient means to permit movement to inoperative retracted position.

In the embodiment of FIGS. 1 and 2, the holding means may be completely stationarily mounted, since it is located on the same side as the drive rollers, and the twisting tube can be removed in radial direction to the left as viewed in FIGS. 1 and 2.

However, the embodiments of FIGS. 3 to 7 have the advantage that when no pressure differential is created between chamber 15 and the other side of the twist tube, the twist tube can lean against the edges of the cutout of the end walls of the holding means and cannot fall off. Of course, during normal operation and rotation of the twisting tube, the same is spaced from the holding means to prevent any mechanical friction.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of twisting arrangements differing from the types described above.

While the invention has been illustrated and described as embodied in a twisting apparatus in which a twisting tube is held in driving engagement with drive means by a pressure differential or air current, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. Yarn twisting arrangement comprising, in combination, drive means having a drive surface; yarn twisting means adapted to be rotated, by being urged in a predetermined direction against said drive surface of said drive means; and means for creating a current of a gaseous medium in said predetermined direction encompassing at least a part of said twisting means for urging the same in said predetermined direction into driving engagement with said driving surface of said drive means.

2. A twisting arrangement according to claim 1 and comprising holding means adapted to support in conjunction with said driving means said twisting means movable between an inoperative position in engagement with said supporting means and out of engagement with said drive means, and an operative position out of engagement with said supporting means and in driving engagement with said driving surface of said drive means.

3. Twisting arrangement comprising, in combination, drive means; yarn twist tube means located adjacent said drive means; and means for creating a fluid pressure differential in the proximity of said twist tube means for holding the same in an operative position in driving connection with said drive means.

4. Twisting arrangement according to claim 3 wherein said fluid pressure differential acts on opposite sides of said tube means and produces a force having a direction transverse to the axial direction of said tube means; and wherein said drive means include a movable drive surface located adjacent said tube means in said transverse direction so that said tube means is urged against said drive surface and driven by the same.

5. Twisting arrangement according to claim 3 wherein said fluid pressure differential acts on opposite sides of said tube means and produces a first force having a direction transverse to the axial direction of said tube means and a second force acting in at least one axial direction of said twist tube means; and wherein said drive means includes a rotatable drive surface located adjacent said tube means in said transverse direction so that said tube means is urged against said drive surface and driven by the same while said axial force holds said tube means against axial movement relative to said drive surface.

6. A twisting arrangement comprising, in combination, drive means; a yarn twist tube having an inoperative position located adjacent said drive means; holding means forming an open chamber with said twist tube located on one side of the same; and gas moving means connected with said holding means and communicating with said chamber for creating a gaseous stream through the same so that the gas pressure acting on said one side of said twist tube is different from the gas pressure on the opposite side of the same, said chamber and said drive means being disposed so that the pressure diiferential acting on said twist tube urges the same toward said drive means into an operative position in driving connection with said drive means.

7. A twisting arrangement according to claim 6 wherein said drive means include roller means engaging the outer surface of said twist tube in said operative position.

8. A twisting arrangement according to claim 7 wherein said roller means include two rollers rotatable about axes parallel to each other and to the axis of said twist tube and simultaneously engaging the same.

9. A twisting arrangement according to claim 7 wherein said roller means has a single axis parallel to the axis of said twisting tube.

It). A twisting arrangement according to claim 6 wherein said drive means is located on the same side of said twist tube as said holding means and said chamber; and wherein said gas moving means include suction means for reducing the gas pressure in said chamber below atmospheric pressure so that the pressure dilferential acting on the twist tube urges the same toward said drive means.

11. A twisting arrangement according to claim 6 wherein said holding means and said chamber are located on one side of said twisting tube, and said drive means are located on the opposite side of said twist tube; and wherein said gas moving means include a source of high pressure gas so that the gas pressure in said chamber is higher than the atmospheric pressure acting on said twist tube whereby the pressure differential acting on said twist tube urges the same toward said drive means.

1 2. A twisting arrangement according to claim 11 wherein said source of high pressure gas is a blower; and including a conduit connecting said blower with said holding means and said chamber.

13. A twisting instrument according to claim 6 wherein said holding means has a substantially semicircular cylindrical inner surface confronting the outer surface of said twist tube spaced from the same in said operative position.

14. A twisting arrangement according to claim 6 wherein said holding means has an inner surface spaced a predetermined distance from the outer surface of said twist tube, and has lips along the edges thereof extending into close proximity of the outer surface of said twist tube means in said operative position to form narrow gaps with the same for restricting the flow of gas through said chamber.

15. A twisting arrangement according to claim 6 wherein said holding means has a substantially semicircular cylindrical inner surface spaced in said operative position a first greater distance from the outer surface of said twist tube, axially extending edges having radially inwardly projecting lips extending into close proximity of the outersurface of said twist tube and being spaced from the same distances smaller than said first greater distance to form narrow gaps restricting the fiow of gas through said chamber.

16. A twisting arrangement according to claim 15 wherein said holding means includes end walls at the ends of said semicircular cylindrical wall, said end walls having semicircular cutouts forming narrow gaps with the outer surface of said twist tube in said operative position for the restricted passage of air.

17. A twisting arrangement according to claim 6 wherein said twisting tube has a cylindrical outer surface having a first diameter; and wherein said holding means includes a semicircular cylindrical wall having a slightly greater diameter than said twisting tube and surrounding the same so that a narrow substantially semicircular gap is formed between said twisting tube and said inner surface of said holding means; and wherein said gas moving means include a source of high pressure gas communicating with said gap so that high pressure gas fills said gap whereby said twist tube is supported on a hydrodynamic bearing formed by a gas cushion in said gap.

18. A twisting arrangement according to claim 17 wherein said drive means includes a shaft and at least one roller secured to said shaft and engaging said twist tube in said operative position, and wherein a plane passing through the axes of said shaft and said twist tube is slanted to a plane of symmetry of said holding means passing through the axis of said twist tube so that a force acting in tangential direction of said roller on the portion of said twist tube'engaged by said roller, is taken up by an air cushion in said gap.

19. A twisting arrangement according to claim 6 wherein said yarn twist tube has a collar with a surface transverse to the axis of said twist tube at least at one end thereof; and wherein said holding means includes a semicircular cylindrical wall having at least one end located adjacent said transverse surface and forming a gap with the same; and wherein said gas moving means include a source of high pressure gas so that the pressure in said chamber acts on said transverse surface to maintain said twist tube in a desired axial position in relation to said drive means.

20. A twsting arrangement according to claim 6 wherein said twist tube has collars at the end thereof, each collar having an annular face transverse to the axis of said twist tube; wherein said holding means includes a substantially semicircular cylindrical wall located on one side of said twist tube and having semicircular edges at the end thereof forming narrow gaps with said annular surfaces of said twist tube; and wherein said gas moving means include a source of high pressure gas connected with said chamber so that the pressure in the same is increased and air escapes through said gaps whereby said twist tube is balanced in axial direction in relation to said drive means.

21. A twisting arrangement according to claim 6 wherein said gas moving means include a conduit connected with said holding means and said chamber; and comprising restrictor valve means located in said conduit for limiting the flow of gas through the same in said inoperative position of said twist tube, or when the twist tube is removed from said holding means.

22. A twisting arrangement according to claim 6 wherein said twist tube has at least one portion having a small diameter and adapted to be engaged by said drive means, and a second portion of larger diameter; and wherein said holding means includes a substantially semicircular cylindrical wall having a greater diameter than said second portion and being located opposite said second portion for forming said chamber with the same.

23. A twisting arrangement according to claim 22 wherein said chamber is a gap of uniform thickness.

24. A twisting arrangement according to claim 23 wherein said drive means includes a roller having an axis parallel to the axis of said twist tube; wherein a plane of symmetry of said semicircular cylindrical wall is slanted to a plane passing through the axes of said twist tube and said drive means whereby the pressure differential acting in said plane of symmetry opposes lateral movement of said twist tube in the direction of the movement of the portion of said drive means which engages said twist tube.

References Cited by the Examiner UNITED STATES PATENTS 3/1964 Noordenbos 57-77.45 3/1966 Mattingly et al. 5777.45 X

OTHER REFERENCES 32-10379, Japanese publication. 

3. TWISTING ARRANGEMENT COMPRISING, IN COMBINATION, DRIVE MEANS; YARN TWIST TUBE MEANS LOCATED ADJACENT SAID DRIVE MEANS; AND MEANS FOR CREATING A FLUID PRESSURE DIFFERENTIAL IN THE PROXIMITY OF SAID TWIST TUBE MEANS FOR HOLDING THE SAME IN AN OPERATIVE POSITION IN DRIVING CONNECTION WITH SAID DRIVE MEANS. 